Safety temperature control



April 20 1926. a

C. WILHJELM :SAFETY TEMPERATURE CONTROL Filed Sept. 18, 1922 Patented Apr. 20, 1926.

CHRISTIAN WILHJELM, OF PHILADELPHIA, PENNSYLVANIA.

sArETy TEMPERATURE CONTROL.

Application filed September 18, 1922. Serial No. 588,930.

To all whom it may concern:

Be it known that I, CHRISTIAN WVILHJELM, a citizen of Denmark, and resident of Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Safety Temperature Controls; of which the followin is a specification.

his invention relates to automatic temperature alarms usable in connection with ovens, boilers, distilling apparatus and other places, where it is desirable that an audible or visible signal or alarm be given when the temperature employed exceeds a predetermined maximum degree.

The object of the invention is to provide an improved automatic temperature alarm adapted for the purposes set forth, and arranged for both portable and permanent installation and use.

In the drawing accompanying this specification and illustrating the invention,

Figure 1 is a view of the device,.showing it partly in section and partly in elevation, together with a diagrammatic illustration of the electric circuit used with the device.

Figure 2 is a diagrammatic illustration of a multiple installation of the device.

Referring to the drawing, the device itself consists of a fuse or wire 1, the melting point of which is known, and which is enclosed in a gas tight tube 2 of porcelain, glass, quartz or similar material. The fuse 1 is secured by Wires as 3, 3 to suitable outside terminals 4, 4.

The numeral 5 denotes a conductor of suitable material having a melting point higher than the fuse 1. Said conductor may be in the form of a wire or rod having an arm 6 adapted to receive and make contact with the one fuse terminal 4.

The conductor 5 is contained within a tube 7 of suitable insulating material. Outside the latter is mounted a tubular conductor 8 provided with a. collar 9. A handle 10,- which may be of wood or other suitable 2 is removably held or mounted between and 111' electrical contact with the two main conductors 5 and 8.

The numeral 15 denotes an alarm or signal box containing an actuating circuit comprising a relay 16 connected in series with a battery 17 and the conductors 5 and 8, and the fuse 1. This circuit. is normally closed, so that the armature 18 of the relay-remains in attracted or raised position.

The box 15 further contains a normally open signal circuit comprising a signal 19 and a battery 20,.and open contacts 21, 21 adapted to be closed by a bridge contact 22 carried by the armature 18 aforesaid.

' Preferably flexible wires 23 serve to connect the alarm device with the signal box.

The oven or apparatus, the temperature of which is to be signalled, is provided with a suitable opening for inserting the device in the proper position. So long as the temperature is below the melting point of the fuse 1, nothing happens. But when the temperature reaches the melting point of the fuse, the latter will melt, the actuating circuit will be broken, hence the armature 18 will drop and the contact 22 will close the signal circuit and a signal will be given;

A new fuse may then be readily inserted by sliding the collar 13 upon the tube 8, removing the old fuse holder and inserting a new one. The collar 13 provides a means for adjustably securing the fuse holder in electric contact with the actuating circuit.

Figure 2 illustrates a plurality of signal boxes 25 which may have visible signalling devices 26. Each box is connected to its separate fuse device 27, constructed like the one described above. Thus, the signal boxes may be mounted in one place for collective inspection, while the fuse devices may be carried about and employed where required.

The device is simple to manufacture, handy to use and operate and effective for its purpose.

It will be understood that the invention is susceptible of changes in the detailed construction without departing from the spirit of the invention or the scope of the appended claim.

I claim A device of the character described com prising a tool consisting of a relatively long tube of insulating material, an electrically conducting rod within the same having one end projecting beyond the end of said tube area and bent at an angle thereto, e sleeve of held between the bent en'd of the said rod electrically conducting material surrounding and the said lug, a handle for said tool, and said tube, a ring of electrically conducting means for connecting said conducting rod 1 material slide lol mounted on said sleeve, and the said conducting sleeve to the termi- 5 means for securing and adjusting the said nals of an electric circuit.

ring on the said sleeve, said ring having :1 lug extending to one side thereof, a fuse element CHRISTIAN WILHJ ELM. 

